Biogenic-to-lithogenic handoff of particulate Zn affects the Zn cycle in the Southern Ocean.

Zinc (Zn) is vital to marine organisms. Its active uptake by phytoplankton results in a substantial depletion of dissolved Zn, and Zn bound to particulate organic matter replenishes dissolved Zn in the ocean through remineralization. However, we found that particulate Zn changes from Zn bound to phosphoryls in cells to recalcitrant inorganic pools that include biogenic silica, clays, and iron, manganese, and aluminum oxides in the Southern Ocean water column. The abundances of inorganic pools increase with depth and are the only phases preserved in sediments. Changes in the particulate-Zn speciation influence Zn bioavailability and explain the decoupling of Zn and phosphorus and the correlation of Zn and silicon in the water column. These findings reveal a new dimension to the ocean Zn cycle, implicating an underappreciated role of inorganic Zn particles and their impact on biological productivity.

Radiological and clinical correlations of the anterior ethmoidal artery in functional endoscopic sinus surgery.

OBJECTIVES: To correlate computed tomography findings and endoscopic localisation of the anterior ethmoidal artery during surgery, and to analyse the intranasal landmarks and abnormalities of the artery. METHOD: The anterior ethmoidal artery was studied with high-resolution computed tomography and endoscopic surgery in 30 patients undergoing functional endoscopic sinus surgery (group A), and with endoscopic dissection on 30 human cadavers (group B). RESULTS: The anterior ethmoidal artery was demonstrated on computed tomography in 25 patients and intra-operatively in 12 (group A). It was identified in 26 cadavers (group B). Dehiscence of bony canal and branching was noted in 10.53 per cent of cases. The mean (± standard deviation) intranasal length of the anterior ethmoidal artery was 7.29 (± 1.21) mm, the distance of the artery from the axilla of the middle turbinate was 16.24 (± 2.75) mm, and the mean distance from the ground lamella was 8.97 (± 1.46) mm. CONCLUSION: High-resolution computed tomography scanning prior to functional endoscopic sinus surgery is mandatory to identify the anterior ethmoidal artery. Endoscopically, the axilla of the middle turbinate and the ground lamella can serve as dependable reference points to identify the artery. Cadaver dissection improves understanding of anatomy.

Strategies to reduce re-ankylosis in temporomandibular joint ankylosis patients.

The purpose of the study was to define a protocol for the prevention of re-ankylosis after surgical management of temporomandibular joint ankylosis (TMJA). The investigators designed a retrospective study on all TMJA patients treated with different treatment modalities from 2013 to 2019. The investigators observed that complete removal of the ankylotic mass particularly on the medial side; use of a piezoelectric scalpel for a clean and smooth osteotomy with copious irrigation to remove bone chips and slurry; less trauma to the local tissue; osteotomy design parallel and inferior osteotomy at the narrowest part, which mostly corresponds to the condylar neck; performance of a coronoidectomy (if mouth opening is <30mm), fat interposition; no intraoperative correction of any pre-existing chin deviation when treated with costochondral graft; patient motivation; and aggressive physiotherapy, and use of a vacuum drain are all important to prevent re-ankylosis, irrespective of the treatment modality. A total of 114 patients (n=152 joints), [bilateral (n=38), unilateral (n=76)] were evaluated retrospectively. Interpositional arthroplasty with fat was performed in n=43, CCG was used for reconstruction in n=30 and total joint replacement (TJR) was done in n=41 patients. Re-ankylosis was seen in n=3 (2.6%) patients (2 in CCG and 1 patient in interpositional arthroplasty). The follow-up ranged from 12-80 months. The results conclude that following the suggested best practice protocol is effective in reducing re-ankylosis.

Role of Carnoy's solution as treatment adjunct in jaw lesions other than odontogenic keratocyst: a systematic review.

Carnoy's solution (CS) is routinely used as adjuvant therapy in the management of odontogenic keratocyst (OKC) and a few other benign lesions. The purpose of this study was to explore the evidence of its application and efficacy in benign lesions other than OKC. We have systematically reviewed published articles to identify the evidence of CS in benign jaw lesions other than OKC following the PRISMA guidelines. The search was conducted in PubMed, Google Scholar, Semantic Scholar, and Cochrane Library database, to find relevant articles from 1980 to March 2020. Finally, 39 studies were analysed in this review. It included studies where CS was used as an adjunct for the benign lesion of the jaw and followed for a minimum of 6 months. Thirty-nine studies with 11 different types of lesion were reported where CS was used as an adjuvant and application time was restricted to 3-5minutes. Recurrence were reported only in ameloblastoma cases [unicystic=10.98% (10/91), mixed=18.18% (26/143)]. Meta-analysis was not possible as all studies were non-controlled in nature. Based on the available data, there was no strong evidence for the use of CS as an adjuvant in the benign lesion of the jaw. Prospective and randomised control studies are recommended for the best stratification for the use of CS.

Does closed treatment of paediatric mandibular condyle fractures result in restitutional remodelling?

The treatment of paediatric mandibular condylar fracture (PMCF) is typically non-operative. The purpose of this study was to determine if non-operative management of PMCF results in a new condylar process of normal morphology to regenerate after closed treatment (restitutional remodelling). The specific aim of the study was to observe restitutional remodelling (RM) in PMCF and review the literature. The investigators designed and implemented a retrospective study on paediatric patients (age<12) with unilateral or bilateral condyle fractures treated with non-operative treatment between January 2005 and July 2015. Patients with complete records and at least 1-year follow-up were included in the study. Primary outcome variable was RM and secondary outcome variables were occlusion, maximal incisal opening (MIO), displacement, infection, facial asymmetry, and signs of temporomandibular joint ankylosis (TMJA). The study evaluated 41 patients {n=57 PMCF, (m:f-35:6)} of unilateral (n=25) and bilateral (n=16) PMCF. Fractured condyles remodelled to normal morphology in all the cases at follow-up. The Wilcoxon test revealed a statistically significant difference in MIO from the preoperative value to postoperative (p=0.001). Occlusion (except 1) was satisfactory in all cases, at follow-up with no gross facial asymmetry. There was no sign of infection at the surgical site (anterior mandible). None of the patients showed signs of TMJA at follow-up. The result of the present study demonstrates that RM of condylar fracture occurs with non-operative management. Non-operative management should be the point of care in PMCF, owing to the rapid RM, bone regeneration, and satisfactory outcome. Review of the literature also supports closed treatment.

Melatonin application differentially modulates the enzymes associated with antioxidative machinery and ascorbate-glutathione cycle during arsenate exposure in indica rice varieties.

Arsenic (As) contamination and accumulation in rice is a serious concern causing severe oxidative damage. Melatonin acts as a protective agent in plant defence against multiple abiotic stresses. The mechanism of antioxidant function of melatonin during As stress in rice genotypes is less studied. In this study, hydroponically-grown As-susceptible (Khitish) and As-tolerant (Muktashri) rice cultivars, subjected to 150 µm arsenate stress, were supplemented with exogenously applied melatonin (20 µm) to examine the plant defence mechanism. Melatonin (Mel) increased root and shoot length, fresh and dry weight, chlorophyll a and b content and activated reducing power and free radical scavenging capacity in both rice cultivars. The role of Mel in the sensitive variety appeared to be more prominent with respect to reduced water saturation deficit by reducing endogenous As and H2 O2 accumulation, and enhancing overall antioxidant capacity by imposing reduced requirement of catalase for ROS detoxification, and restoring As-inhibited activity of glutathione-S-transferase, glutathione peroxidase and dehydroascorbate reductase. In contrast, melatonin treatment in the tolerant cultivar required reduced involvement of ascorbate peroxidase to deal with As toxicity, and complemented the stress-mediated inhibition of guaiacol peroxidase activity. Isozyme profiling also established extensive varietal differences with regard to induction of new isoform(s) by Mel during As treatment. This study provides clear insights into mechanistic details of the regulation of antioxidative enzymes by melatonin in contrasting rice genotypes, which may prove helpful in generating As tolerance in susceptible rice varieties grown in marginalized soils, thereby improving crop yield and productivity.

Digital workflow for treating comminuted anterior mandibular fracture - A technical note.

Comminuted mandibular fracture poses a surgical challenge. Extensive comminution and absence of reference adds complexity particularly in anterior region. In this technical note, we describe a novel application of virtual surgical planning combined with 3D printing which grants precise anatomic reduction in such cases. Computed Tomography data (mandible) of another patient of same age and sex was utilized to create reference model by virtual surgical planning. Virtually created model was 3D printed and utilized for precontouring the reconstruction plate which assisted in achieving satisfactory outcome.

Can costochondral grafts fulfil ramus-condyle unit reconstruction goals in children with temporomandibular joint ankylosis?

The purpose of this study was to analyse whether costochondral grafts (CCG) fulfil temporomandibular joint (TMJ) reconstructive goals in children with TMJ ankylosis. A total of 23 patients (12 male, 11 female, aged 3-16 years) with unilateral or bilateral TMJ ankylosis operated on between January 2014 to April 2018 were included in the study. Maximal incisal opening (MIO), frequency of reankylosis, and growth of CCG, were evaluated at one month and six months for one year, and after that once yearly. Mouth opening changes with time were assessed by the Friedman test and growth was compared at follow up and analysed using the paired t test. Mean (range) follow up was 18 (12-48) months. Study results revealed follow up MIO at 12 months was highly significant (p=0.001). Out of 27 CCG studied, only one graft had undergone re-ankylosis. Based on the predetermined criteria using condylion to gnathion (Co-Gn) measurement in the posteroanterior cephalogram, CCG were categorised into optimum, sub-optimum, and overgrowth. However, long-standing TMJ ankylosis cases still displayed mandibular asymmetry at the end of the study, even with "optimal growth" radiographically. Overall comparison between the immediate postoperative and last follow up Co-Gn measurements in either unilateral or bilateral cases was not significant. CCG with functional matrix maintained the growth of the mandible and MIO in TMJ ankylosis. It can be concluded that CCG partially fulfils reconstructive goals; however, patients need to be followed up till the end of puberty for a substantive conclusion.

Fixation of subcondylar fractures of the mandible: a randomized clinical trial comparing one trapezoidal plate with two miniplates.

Subcondylar fracture of the mandible accounts for 25-35% of all mandibular fractures. In the past, most subcondylar fractures were managed non-surgically. The traditional method of fixation for subcondylar fractures uses two miniplates; however some bench studies have reported that trapezoidal plates are superior. The aim of this study was to compare the outcomes of subcondylar fractures fixed either with two non-parallel straight miniplates or with one trapezoidal plate. A randomized clinical trial was designed and implemented. Fifty-two consecutive patients with subcondylar fractures were recruited. All patients underwent surgery via a retromandibular approach. The time taken for fixation of the plate after fracture reduction and postoperative outcomes and complications were compared between the groups. The trapezoidal plates were superior in terms of ease of adaptation and time taken for fixation (P= 0.0001). Plate fracture was observed only in the two miniplates group, in four (16%) patients. Outcomes were similar in the two groups in terms of occlusion, mouth opening, protrusion, and lateral excursion. In conclusion, both systems - two miniplates and the trapezoidal plate - provide functionally stable fixation. The outcome was significantly better for the trapezoidal plate than for two miniplates regarding the time taken for insertion and ease of adaptation, but not for other parameters.

Surgical management of oral submucous fibrosis with "Seagull-nasolabial flap" combined with short-term oral pentoxifylline for preventing relapse.

The aim of the study was to evaluate the effectiveness of seagull-shaped nasolabial flap (NLF) along with adjunctive short-term oral pentoxifylline in the surgical reconstruction of oral sub mucous fibrosis (OSMF) following fibrotomy. We retrospectively evaluated 18 patients with grade IV oral sub mucous fibrosis treated by NLF. There were 3 females and 15 males. All patients were classified as stage IV OSMF with a mean preoperative mouth opening of 8.11±3.38mm. Postoperatively, patients were administered 400mg of pentoxifylline (PTX) thrice daily for 3 months. Patients were followed up at one month, six months and one year. Mouth opening, presence or absence of malignant transformation, relapse and complications were recorded at each follow-up. We found statistically significant increase in mouth opening from 8.11±3.3 to 37.67±3.74 in the postoperative period. The complications associated with NLF were very minimal. The PTX was well tolerated by all the patients. There was no incidence of relapse or rebound fibrosis seen in our series. To the best of our knowledge, this is the first time that oral pentoxifylline has been administered along with surgical treatment of oral submucous fibrosis to prevent relapse. The use of oral PTX as an adjunct along with surgical reconstruction in OSMF improves mouth opening, reduces burning sensation and relapse.

Does methylprednisolone improve postoperative outcomes after mandibular third molar surgery? A systematic review and meta-analysis.

This systematic review and meta-analysis was performed to investigate whether methylprednisolone (MP) administered via any route improves postoperative outcomes (pain, trismus, and oedema) following mandibular third molar surgery. An electronic search of the PubMed, Scopus, Cochrane CENTRAL, and Google Scholar databases was performed to identify studies published in English up until January 2018. A total of 28 studies were included in the review: 25 randomized clinical trials (RCTs) and three controlled clinical trials. Studies were grouped according to the route of administration of MP for qualitative and quantitative analysis. Three studies were of 'high' quality and 22 were of 'medium' quality; three studies had a high risk of bias. Within the purview of the limitations of this review, the results showed that MP administered via any route significantly improves oedema in the early postoperative period, but has no effect on late postoperative oedema. Oral and intra-masseteric MP also seems to reduce pain and trismus in the early postoperative period. The results also indicate that oral MP may reduce late postoperative pain, while intra-masseteric MP may improve the late trismus outcome. More high quality RCTs are required to provide stronger evidence on the use of MP in third molar surgery.

Single puncture versus standard double needle arthrocentesis for the management of temporomandibular joint disorders: A systematic review.

The aim of this systematic review was to investigate the current evidence in order to assess the efficacy of single puncture arthrocentesis vs standard double needle arthrocentesis in the management of temporomandibular joint(TMJ) disorders. An electronic search of the PubMed, Scopus, Cochrane CENTRAL and Google Scholar databases was performed to identify English studies published up until October 2017. Eligible studies were selected based on inclusion criteria and included randomised controlled trials(RCTs) comparing single puncture arthrocentesis and standard double needle arthrocentesis for the management TMJ disorders. The initial screening identified 984 records, of which only 5 fulfilled the inclusion criteria. A high degree of heterogeneity was found in the 5 studies with each reporting different sample selection and arthrocentesis protocol. All 5 studies reported no difference in reduction in pain intensity and improvement in maximal mouth opening between the single puncture technique and standard double needle technique. This review provides some evidence that single puncture arthrocentesis is clinically as efficacious as standard double needle arthrocentesis. There is a need of well-designed RCT with standard protocol of arthrocentesis comparing different single puncture techniques and standard double needle technique for the management of TMJ disorders.

Bone density and microarchitecture in hepatitis C and HIV-coinfected postmenopausal minority women.

We found that HIV+/HCV+ women had 7-8% lower areal bone mineral density (aBMD) by dual-energy x-ray absorptiometry (DXA) at the spine, hip, and radius (p < 0.01) and 5-7% lower volumetric BMD (vBMD) by central quantitative computed tomography (cQCT) at the spine and hip (p < 0.05). These data suggest that true deficits in vBMD may contribute to bone fragility and excess fractures reported in HIV+/HCV+ women. INTRODUCTION: aBMD by DXA is lower in persons coinfected with HIV and HCV (HIV+/HCV+) than with HIV monoinfection (HIV+). However, weight is often also lower with HCV infection, and measurement of aBMD by DXA can be confounded by adiposity; we aimed to determine whether true vBMD is also lower in HIV+/HCV+ coinfection. METHODS: We measured aBMD of the lumbar spine (LS), total hip (TH), femoral neck (FN), and ultradistal radius (UDR) by DXA and vBMD of the spine and hip by cQCT and of the distal radius and tibia by high-resolution peripheral QCT (HRpQCT) in 37 HIV+/HCV+ and 119 HIV+ postmenopausal women. Groups were compared using Student's t tests with covariate adjustment by multiple regression analysis. RESULTS: HIV+/HCV+ and HIV+ women were of similar age and race/ethnicity. HIV+/HCV+ women had lower body mass index (BMI) and trunk fat and were more likely to smoke and less likely to have a history of AIDS. In HIV+/HCV+ women, aBMD by DXA was 7-8% lower at the LS, TH, and UDR (p < 0.01). Similarly, vBMD by cQCT was 5-7% lower at the LS and TH (p < 0.05). Between-group differences in LS aBMD and vBMD remained significant after adjustment for BMI, smoking, and AIDS history. Tibial total vBMD by HRpQCT was 10% lower in HIV+/HCV+ women. CONCLUSION: HIV+/HCV+ postmenopausal women had significantly lower spine aBMD and vBMD. These deficits in vBMD may contribute to bone fragility and excess fractures reported in HIV+/HCV+ women.

Closed technique for naso-orbito-ethmoid fracture management: Technical note.

Trauma to the naso-orbito-ethmoid region invariably results in detachment of medial canthal tendon. The shape of medial canthus is of important esthetic and functional concern. Accurate reposition of the medial canthus is important to achieve normal form and function. The various available techniques advocate open approach leaving an obvious scar in the esthetically prominent region. This technique intends to address these fractures through a closed approach with the possibility to make finer adjustments as and when required. We report the experience of treating 4 naso-orbito-ethmoid fractures with a new innovative technique with predictable results.

New HBV subgenotype D9, a novel D/C recombinant, identified in patients with chronic HBeAg-negative infection in Eastern India.

Genome diversity is a hallmark of hepatitis B virus (HBV), which allowed its classification into 10 genotypes (A-J) and numerous subgenotypes. Among them, Genotype D is currently segregated into eight subgenotypes (D1-D8). Here, we report the identification and characterization of a novel subgenotype within genotype D of HBV from chronic hepatitis B e antigen (HBeAg)-negative patients of Eastern India. Phylogenetic tree analysis based on complete genome sequences revealed that six of 39 HBV/D isolates formed a distinct cluster supported by high bootstrap value and had nucleotide divergence >4% relative to the known D subgenotypes (D1-D8), justifying their assignment into a new subgenotype (D9). By comparing the amino acid sequences of the four ORFs of HBV/D9 with D1-D8, 36 specific residues, including a unique one (E(112) in the core region), were identified that could be considered as a signature of D9. Further analysis by Simplot, BootScan and jpHMM demonstrated that D9 resulted from a discrete recombination with genotype C over the precore-core region. This type of recombination has not been described previously as all C/D recombinants reported so far possessed genotype C backbones with mosaic fragments derived from HBV/D. Interestingly, compared to other subgenotypes of HBV/D, D9 isolates had a higher frequency of mutations (A1762T and G1764A) in the basal core promoter region that had been implicated in the development of hepatocellular carcinoma. Further investigations are needed to determine the overall prevalence and clinical significance of these newly characterized D9 strains and to assess the impact of inter-genotypic recombination on viral properties.

Dissimilatory sulphate reduction in hypersaline coastal pans: an integrated microbiological and geochemical study.

Here, we report on the spatial and temporal variation in sulphate-reducing bacterial community structure and activity in three hypersaline coastal pans. Community structure was determined using denaturing gradient gel electrophoresis (DGGE). Cluster analysis of DGGE patterns indicated that similar microbial populations were generally found in individual pans but varied from one pan to the other. Sulphate reducing bacteria (SRB) were quantified by competitive polymerase chain reaction based on the amplification of the dsrAB genes. Cell numbers and in situ sulphate reduction activities varied between seasons and pans but in general showed low variation in depth. Sulphate reduction activity was not correlated with microbial population size indicating that community composition is relevant for specific microbial processes. Principal component analysis coupled with correlation analyses suggested that salinity, sulphate concentration, C/N ratio and pH were the most important factors in explaining variations in SRB community composition. Most sequences derived from DGGE amplicons belonged to members of the Desulfobacteraceae and Desulfohalobiaceae families.

Chemically and geographically distinct solid-phase iron pools in the Southern Ocean.

Iron is a limiting nutrient in many parts of the oceans, including the unproductive regions of the Southern Ocean. Although the dominant fraction of the marine iron pool occurs in the form of solid-phase particles, its chemical speciation and mineralogy are challenging to characterize on a regional scale. We describe a diverse array of iron particles, ranging from 20 to 700 nanometers in diameter, in the waters of the Southern Ocean euphotic zone. Distinct variations in the oxidation state and composition of these iron particles exist between the coasts of South Africa and Antarctica, with different iron pools occurring in different frontal zones. These speciation variations can result in solubility differences that may affect the production of bioavailable dissolved iron.

Diffusion-weighted imaging in the evaluation of odontogenic cysts and tumours.

OBJECTIVE: The differentiation between keratocystic odontogenic tumour (KCOT) and other cystic/predominantly cystic odontogenic tumours is difficult on conventional CT and MR sequences as there is overlap in the imaging characteristics of these lesions. The purpose of this study was to evaluate the role of diffusion-weighted imaging (DWI) and to assess the performance of apparent diffusion coefficients (ADCs) in the differential diagnosis of odontogenic cysts and tumours. METHODS: 20 patients with odontogenic cysts and tumours of the maxillomandibular region were examined with DWI. Diffusion-weighted images were obtained with a single-shot echoplanar technique with b-values of 0, 500 and 1000 s mm(-2). An ADC map was obtained at each slice position. RESULTS: The cystic areas of ameloblastoma (n=10) showed free diffusion with a mean ADC value of 2.192±0.33×10(-3) mm(2) s(-1), whereas the solid areas showed restricted diffusion with a mean ADC value of 1.041±0.41×10(-3) mm(2) s(-1). KCOT (n=5) showed restricted diffusion with a mean ADC value of 1.019±0.07×10(-3) mm(2) s(-1). There was a significant difference between the ADC values of KCOT and cystic ameloblastoma (p<0.01, Mann-Whitney U-test). The cut-off with which KCOT and predominantly cystic ameloblastomas were optimally differentiated was 2.013×10(-3) mm(2) s(-1), which yielded 100% sensitivity and 100% specificity. CONCLUSION: DWI can be used to differentiate KCOT from cystic (or predominantly cystic) odontogenic tumours.